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-rw-r--r--util-linux/seedrng.c148
1 files changed, 59 insertions, 89 deletions
diff --git a/util-linux/seedrng.c b/util-linux/seedrng.c
index 2950acd..d82a942 100644
--- a/util-linux/seedrng.c
+++ b/util-linux/seedrng.c
@@ -6,7 +6,7 @@
*/
//config:config SEEDRNG
-//config: bool "seedrng (3.8 kb)"
+//config: bool "seedrng (2.6 kb)"
//config: default y
//config: help
//config: Seed the kernel RNG from seed files, meant to be called
@@ -50,53 +50,38 @@
#define GRND_INSECURE 0x0004 /* Apparently some headers don't ship with this yet. */
#endif
-#ifndef LOCALSTATEDIR
-#define LOCALSTATEDIR "/var/lib"
-#endif
-#ifndef RUNSTATEDIR
-#define RUNSTATEDIR "/var/run"
+#if ENABLE_PID_FILE_PATH
+#define PID_FILE_PATH CONFIG_PID_FILE_PATH
+#else
+#define PID_FILE_PATH "/var/run"
#endif
-#define DEFAULT_SEED_DIR LOCALSTATEDIR "/seedrng"
-#define DEFAULT_LOCK_FILE RUNSTATEDIR "/seedrng.lock"
+#define DEFAULT_SEED_DIR "/var/lib/seedrng"
+#define DEFAULT_LOCK_FILE PID_FILE_PATH "/seedrng.lock"
#define CREDITABLE_SEED_NAME "seed.credit"
#define NON_CREDITABLE_SEED_NAME "seed.no-credit"
static char *seed_dir, *lock_file, *creditable_seed, *non_creditable_seed;
enum seedrng_lengths {
- MAX_SEED_LEN = 512,
- MIN_SEED_LEN = SHA256_OUTSIZE
+ MIN_SEED_LEN = SHA256_OUTSIZE,
+ MAX_SEED_LEN = 512
};
-#ifndef DIV_ROUND_UP
-#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
-#endif
-
static size_t determine_optimal_seed_len(void)
{
- size_t ret = 0;
char poolsize_str[11] = { 0 };
- int fd = open("/proc/sys/kernel/random/poolsize", O_RDONLY);
- if (fd < 0 || read(fd, poolsize_str, sizeof(poolsize_str) - 1) < 0) {
- fprintf(stderr, "WARNING: Unable to determine pool size, falling back to %u bits: %s\n", MIN_SEED_LEN * 8, strerror(errno));
- ret = MIN_SEED_LEN;
- } else
- ret = DIV_ROUND_UP(strtoul(poolsize_str, NULL, 10), 8);
- if (fd >= 0)
- close(fd);
- if (ret < MIN_SEED_LEN)
- ret = MIN_SEED_LEN;
- else if (ret > MAX_SEED_LEN)
- ret = MAX_SEED_LEN;
- return ret;
+ if (open_read_close("/proc/sys/kernel/random/poolsize", poolsize_str, sizeof(poolsize_str) - 1) < 0) {
+ bb_perror_msg("unable to determine pool size, falling back to %u bits", MIN_SEED_LEN * 8);
+ return MIN_SEED_LEN;
+ }
+ return MAX(MIN((bb_strtoul(poolsize_str, NULL, 10) + 7) / 8, MAX_SEED_LEN), MIN_SEED_LEN);
}
static int read_new_seed(uint8_t *seed, size_t len, bool *is_creditable)
{
ssize_t ret;
- int urandom_fd;
*is_creditable = false;
ret = getrandom(seed, len, GRND_NONBLOCK);
@@ -109,21 +94,16 @@ static int read_new_seed(uint8_t *seed, size_t len, bool *is_creditable)
.events = POLLIN
};
if (random_fd.fd < 0)
- return -errno;
- *is_creditable = poll(&random_fd, 1, 0) == 1;
+ return -1;
+ *is_creditable = safe_poll(&random_fd, 1, 0) == 1;
close(random_fd.fd);
} else if (getrandom(seed, len, GRND_INSECURE) == (ssize_t)len)
return 0;
- urandom_fd = open("/dev/urandom", O_RDONLY);
- if (urandom_fd < 0)
- return -errno;
- ret = read(urandom_fd, seed, len);
- if (ret == (ssize_t)len)
- ret = 0;
- else
- ret = -errno ? -errno : -EIO;
- close(urandom_fd);
- return ret;
+ if (open_read_close("/dev/urandom", seed, len) == (ssize_t)len)
+ return 0;
+ if (!errno)
+ errno = EIO;
+ return -1;
}
static int seed_rng(uint8_t *seed, size_t len, bool credit)
@@ -138,69 +118,63 @@ static int seed_rng(uint8_t *seed, size_t len, bool credit)
};
int random_fd, ret;
- if (len > sizeof(req.buffer))
- return -EFBIG;
+ if (len > sizeof(req.buffer)) {
+ errno = EFBIG;
+ return -1;
+ }
memcpy(req.buffer, seed, len);
random_fd = open("/dev/random", O_RDWR);
if (random_fd < 0)
- return -errno;
+ return -1;
ret = ioctl(random_fd, RNDADDENTROPY, &req);
if (ret)
ret = -errno ? -errno : -EIO;
close(random_fd);
- return ret;
+ errno = -ret;
+ return ret ? -1 : 0;
}
static int seed_from_file_if_exists(const char *filename, bool credit, sha256_ctx_t *hash)
{
uint8_t seed[MAX_SEED_LEN];
ssize_t seed_len;
- int fd, dfd, ret = 0;
+ int dfd = -1, ret = 0;
- fd = open(filename, O_RDONLY);
- if (fd < 0 && errno == ENOENT)
- return 0;
- else if (fd < 0) {
- ret = -errno;
- fprintf(stderr, "ERROR: Unable to open seed file: %s\n", strerror(errno));
- return ret;
- }
dfd = open(seed_dir, O_DIRECTORY | O_RDONLY);
if (dfd < 0) {
ret = -errno;
- close(fd);
- fprintf(stderr, "ERROR: Unable to open seed directory: %s\n", strerror(errno));
- return ret;
+ bb_simple_perror_msg("unable to open seed directory");
+ goto out;
}
- seed_len = read(fd, seed, sizeof(seed));
+ seed_len = open_read_close(filename, seed, sizeof(seed));
if (seed_len < 0) {
- ret = -errno;
- fprintf(stderr, "ERROR: Unable to read seed file: %s\n", strerror(errno));
- }
- close(fd);
- if (ret) {
- close(dfd);
- return ret;
+ if (errno != ENOENT) {
+ ret = -errno;
+ bb_simple_perror_msg("unable to read seed file");
+ }
+ goto out;
}
if ((unlink(filename) < 0 || fsync(dfd) < 0) && seed_len) {
ret = -errno;
- fprintf(stderr, "ERROR: Unable to remove seed after reading, so not seeding: %s\n", strerror(errno));
+ bb_simple_perror_msg("unable to remove seed after reading, so not seeding");
+ goto out;
}
- close(dfd);
- if (ret)
- return ret;
if (!seed_len)
- return 0;
+ goto out;
sha256_hash(hash, &seed_len, sizeof(seed_len));
sha256_hash(hash, seed, seed_len);
- fprintf(stdout, "Seeding %zd bits %s crediting\n", seed_len * 8, credit ? "and" : "without");
+ printf("Seeding %zd bits %s crediting\n", seed_len * 8, credit ? "and" : "without");
ret = seed_rng(seed, seed_len, credit);
if (ret < 0)
- fprintf(stderr, "ERROR: Unable to seed: %s\n", strerror(-ret));
- return ret;
+ bb_simple_perror_msg("unable to seed");
+out:
+ if (dfd >= 0)
+ close(dfd);
+ errno = -ret;
+ return ret ? -1 : 0;
}
int seedrng_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
@@ -236,14 +210,12 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
if (!(opt & OPT_l) || !lock_file)
lock_file = xstrdup(DEFAULT_LOCK_FILE);
skip_credit = opt & OPT_n;
- creditable_seed = xasprintf("%s/%s", seed_dir, CREDITABLE_SEED_NAME);
- non_creditable_seed = xasprintf("%s/%s", seed_dir, NON_CREDITABLE_SEED_NAME);
+ creditable_seed = concat_path_file(seed_dir, CREDITABLE_SEED_NAME);
+ non_creditable_seed = concat_path_file(seed_dir, NON_CREDITABLE_SEED_NAME);
umask(0077);
- if (getuid()) {
- fprintf(stderr, "ERROR: This program requires root\n");
- return 1;
- }
+ if (getuid())
+ bb_simple_error_msg_and_die("this program requires root");
sha256_begin(&hash);
sha256_hash(&hash, seedrng_prefix, strlen(seedrng_prefix));
@@ -252,14 +224,12 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
sha256_hash(&hash, &realtime, sizeof(realtime));
sha256_hash(&hash, &boottime, sizeof(boottime));
- if (mkdir(seed_dir, 0700) < 0 && errno != EEXIST) {
- fprintf(stderr, "ERROR: Unable to create \"%s\" directory: %s\n", seed_dir, strerror(errno));
- return 1;
- }
+ if (mkdir(seed_dir, 0700) < 0 && errno != EEXIST)
+ bb_simple_perror_msg_and_die("unable to create seed directory");
lock = open(lock_file, O_WRONLY | O_CREAT, 0000);
if (lock < 0 || flock(lock, LOCK_EX) < 0) {
- fprintf(stderr, "ERROR: Unable to open lock file: %s\n", strerror(errno));
+ bb_simple_perror_msg("unable to open lock file");
program_ret = 1;
goto out;
}
@@ -274,7 +244,7 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
new_seed_len = determine_optimal_seed_len();
ret = read_new_seed(new_seed, new_seed_len, &new_seed_creditable);
if (ret < 0) {
- fprintf(stderr, "ERROR: Unable to read new seed: %s\n", strerror(-ret));
+ bb_simple_perror_msg("unable to read new seed");
new_seed_len = SHA256_OUTSIZE;
strncpy((char *)new_seed, seedrng_failure, new_seed_len);
program_ret |= 1 << 3;
@@ -283,20 +253,20 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
sha256_hash(&hash, new_seed, new_seed_len);
sha256_end(&hash, new_seed + new_seed_len - SHA256_OUTSIZE);
- fprintf(stdout, "Saving %zu bits of %s seed for next boot\n", new_seed_len * 8, new_seed_creditable ? "creditable" : "non-creditable");
+ printf("Saving %zu bits of %s seed for next boot\n", new_seed_len * 8, new_seed_creditable ? "creditable" : "non-creditable");
fd = open(non_creditable_seed, O_WRONLY | O_CREAT | O_TRUNC, 0400);
if (fd < 0) {
- fprintf(stderr, "ERROR: Unable to open seed file for writing: %s\n", strerror(errno));
+ bb_simple_perror_msg("unable to open seed file for writing");
program_ret |= 1 << 4;
goto out;
}
if (write(fd, new_seed, new_seed_len) != (ssize_t)new_seed_len || fsync(fd) < 0) {
- fprintf(stderr, "ERROR: Unable to write seed file: %s\n", strerror(errno));
+ bb_simple_perror_msg("unable to write seed file");
program_ret |= 1 << 5;
goto out;
}
if (new_seed_creditable && rename(non_creditable_seed, creditable_seed) < 0) {
- fprintf(stderr, "WARNING: Unable to make new seed creditable: %s\n", strerror(errno));
+ bb_simple_perror_msg("unable to make new seed creditable");
program_ret |= 1 << 6;
}
out:
generated by cgit v1.1 at 2024-11-02 20:15:28 +0000